Using street view, you can often see "Social Security" on a building or sign.

Social Security Office Directions and Notes :

2 MILES NORTH OF THE 22 FWY. MAJOR CROSS STREETS ARE CHAPMAN AVE AND GILBERT ST. OFFICE IS LOCATED HALF A BLOCK NORTH OF CHAPMAN AVE ON THE EAST SIDE OF GILBERT ST. GILBERT ST. IS BETWEEN AND PARALLEL TO BROOKHURST AND MAGNOLIA

Garden Grove Social Security Office Notes

You can do many things like signup for retirement
benefits online at ssa.gov.
Social Security office hours have been reduced the past few years.
Now almost all Social Security offices have the same hours of 9:00
to noon on Wednesdays, and 9:00 to 4:00 on other weekdays.
Fridays may be a bit less crowded. Try to get an appointment by
phone first.